Flow assurance is a term commonly used to cover a wide range of flow-related issues. These issues typically include: hydrate formation, wax formation, asphaltene formation, emulsions, foaming, scale formation, sand production, slugging, materials-related issues.
Source: API RP 17A, Design and Operation of Subsea Production Systems—General Requirements and Recommendations, Fourth Edition, Reaffirmed 2011. Global Standards
Flow assurance is the control or mitigation of the deposition/formation of hydrates, wax, asphaltenes, and scale in the production flow path. Many factors affect flow assurance such as fluid composition, pressure, flow rate and temperature. Fluids in the wellbore can experience significant temperature changes, and plugs can form as a result. Flow assurance is provided by chemical and/or thermal management. Design of the total system should consider the wellhead and tree, which have the highest heat loss. Some methods of prevention used in industry are as follows: VIT; tubing coating or finish; gas-filled “A” annulus near/above the mudline; low heat transfer fluid in the annulus; injection of fluids to minimize/prevent the effects of hydrates, paraffin, scale through “control lines” strapped to the outside of the tubing; placement of SCSSVs below the top of hydrate/wax/asphaltene formation depth.
Source: API RP 96, Deepwater Well Design and Construction, First Edition, March 2013. Global Standards